In recent years, vehicle window glass has undergone significant evolution and increasingly dramatic styling have brought about the use of cylindrically curved door window panes as a contribution to overall vehicle design. Coupled with this, a redesign effort is being made to provide a flush finish between the window panels and the exterior of the vehicle to further enhance appearance and aerodynamics and to reduce wind noise. For example, as regards the side door windows, it is desired that the window panel be flush with the exterior door panel at the beltline, as well as at the roof panel and pillars, rather than being inset transversely within the framework of the door as in previous years.
Being flush at these surfaces requires a unique construction of the window position regulating mechanism. It also requires a unique system for sealing the edges of the window panel around the entire framework.
It is known, for example, to achieve a flush edge condition in a sedan type vehicle having a door frame that has vertical portions to provide front and rear (generally vertically arranged and curved) guide channels secured to the interior door panel, and to provide within each guide channel a plastic guide affixed to the window and in rolling or sliding engagement with the guide channel. For one previous concept, the plastic guide is curved similarly to the window and increases in transverse cross-sectional width from the top of the window to the bottom of the window such that as the window is raised, the lower edge portion of the window will move progressively outward toward the outer door panel and will be nearly flush with the outer door at the beltline at its fully raised position. Such an arrangement is shown in U.S. Pat. No. 4,561,211.
Other systems are known such as shown in U.S. Pat. Nos. 2,979,327; 4,575,967; and 4,783,930 for accomplishing a substantially flush condition of the vehicle side door window wherein a slightly cylindrically curved window or flat or nearly flat window is guided by a pair of guide channels fixed within the door panel at the front and rear edges thereof with each guide channel including (at a position just above or just below the beltline) a track or guide channel portion inclined relatively abruptly and outwardly such that when the window reaches its raised position or nearly raised position, the lower edge of the window will be translated laterally outwardly into a substantially flush position at the beltline and at the upper edge of the window with the vehicle exterior. In each case, the window pivots basically about its upper edge as the lower edge of the window swings laterally outward. Such a system may work relatively well with a constant curvature or with flat or nearly flat glass, since the compression seal used for weatherstripping the window frame can accommodate a small degree of compression or lateral transfer. With the more cylindrically curved windows of the present day vehicles, such systems would prove unsatisfactory.
Yet another substantially flush vehicle door assembly is shown in U.S. Pat. No. 4,771,575 which like those mentioned immediately above, causes a window to pivot about its upper edge as the lower edge of the window is laterally transferred to and from the exterior door panel. The means by which the lateral transfer is effected, rather than being dependent upon the shape of the guide track, is accomplished by means of the interior seal affixed to the window sash pipe bearing against the inner weatherstrip seal of the inner door panel and being forced in the outward direction as the window is raised; conversely when the window is the interior seal disengages the inner weatherstrip seal and thereby allows the lower edge of the window to swing inward.
Another system for providing a flush vehicle window is shown in U.S. Pat. No. 4,788,794. As with the present invention, the window is caused to pivot at a position intermediate that of the beltline and the upper edge of the window such that as the window is raised, its lower edges laterally traverses outward to a substantially flush position with the beltline, and the upward edge of the window at its inner surface is caused to traverse laterally inwardly to bear against the weatherstrip seal running longitudinally at the roof panel and vertically downwardly at the front and rear edges of the window to the point of the pivot. The pivot point is established by an upper guide pin which rides within a curved track vertically arranged at the front and rear of the door panel. A lower guide pin is affixed to the lower edge of the window and as it approaches the fully raised window position is caused to enter in an abruptly curved portion of the track extending outwardly toward the exterior door panel such that the lower portion of the window is translated laterally outwardly in a manner similar to certain of the above-mentioned patents.
Unlike the present invention, the guide channel is seen to be of fairly expensive construction since the upper guide pin is seen to be riding on a rail and the lower guide pin within a groove, rather than each riding along the same guide surface. It is also subject to disengagement from tolerances and loading of the window. Further, the compression seal provided between the beltline and the pivot point must be deflected more when the window is being moved than when the window is at rest fully closed. Generally, a flexible lip type seal as shown has not proven satisfactory, particularly in cold weather conditions, to accommodate the degree of window movement involved.
None of the aforementioned systems is seen to provide a window position regulating assembly which will (i) establish a perfectly flush interface between the window and the vehicle exterior at all points about the perimeter of the window, or (ii) provide a reliable full seal about the perimeter of the window, or (iii) provide a simply constructed, economical and highly reliable mechanism for accomplishing these results. They also are limited in the amount of irregular shape of window surface which can be accommodated and the consideration for accommodation in an unframed door (i.e., a hardtop window).